The present invention relates to motors for watercraft and, more specifically, to motors that are designed to propel a watercraft using hydrogen as a fuel source.
1. Background of the Invention
For a number of reasons, hydrogen has often been proposed for use as motor fuel. One important reason for considering hydrogen as a motor fuel is that, when hydrogen is burned in air to release energy, water is the primary byproduct. Carbon dioxide is not produced, so hydrogen creates fewer greenhouse gasses at the point of combustion than gasoline when used as a fuel source.
In addition, certain primary energy sources, such as solar and electrical energy, do not lend themselves to mobile applications. Solar power does not generate sufficient power on a continuous basis for many mobile applications, and the storage of electricity generated by solar or other means in batteries presents additional problems. These primary energy sources can, however, be readily used to convert water into hydrogen using electrolysis. The hydrogen so produced can be stored and burned at locations remote from the solar or other source of electrical energy.
Currently, hydrogen can be obtained relatively inexpensively from methane, or natural gas, using steam methane reforming; in the near term, hydrogen can thus be produced from methane as long as methane is available cheaply and in large quantities.
In the future, it may be practical to generate hydrogen using either a fermentation process or a photosynthesis process; either of these processes might result in a clean, renewable source of hydrogen for use as a motor fuel.
For these and other reasons, the need exists for efficient, reliable, and inexpensive motors that operate with hydrogen as a fuel source.
2. Related Art
The Applicant is aware of a number of attempts to use hydrogen as a substitute fuel for gasoline or diesel oil in conventional internal combustion engines. An adapted internal combustion engine converts the chemical energy of the hydrogen directly into mechanical energy without the intermediate step of acting on a working fluid. The combustion cycle thus may not be optimum for efficient operation of one or the other of the combustion of the hydrogen or the conversion of the released chemical energy into mechanical work.
The Applicant is also aware of an attempt to propel watercraft using hydrogen as a fuel. A water path was created from the bow to the stern of the boat. A combustion chamber was connected to the water path such that water at least partly filled the combustion chamber before each combustion cycle. A hydrogen/oxygen mixture was ignited within the combustion chamber such that the ignited mixture acted directly on the water in the combustion chamber. The water was thus forced out of the combustion chamber and directly out of the back of the boat to propel the boat in the water. Especially at low speeds, this system would cause the boat to lurch forward with each combustion cycle because of the direct relationship between the combustion cycle and the thrust obtained by the water forced out of the back of the boat.
The present invention is a system for propelling a watercraft using hydrogen. The system comprises a combustion chamber, an accumulator system, an ignition system, and a propulsion control system. The combustion chamber defines an upper portion and a lower portion. The accumulator system stores pressurized fluid. A first check valve is arranged to allow water to flow from the exterior of the watercraft into the lower portion of the combustion chamber. A second check valve is arranged to allow water to flow from the lower portion of the combustion chamber to the accumulator system. A propulsion control valve is arranged to control the flow of water from the accumulator system to the exterior of the watercraft. A mixture of hydrogen and oxygen is introduced into the upper portion of the combustion chamber. An ignition system for igniting the mixture of hydrogen and oxygen in the combustion chamber to create expanding gases that force the water in the lower portion of the combustion chamber into the accumulator system through the second check valve. The propulsion control system operates the propulsion control valve to allow water in the accumulator system to flow to the exterior of the watercraft at a desired flow rate.